1. Field of the Invention
The present invention relates to a self-closing filler cap for a fuel tank filler neck, the neck including a restrictive flap hinged thereto, the invention relating more particularly to a self-closing filler cap configured adapted for use with an automatic fuelling system.
2. Description of Prior Art
Such self-closing filler caps for automotive vehicle fuel tanks are known, they enabling the vehicle operator to fuel his vehicle without having to remove the filler cap from the filler neck.
Such filler caps generally comprise a cap body with either screw threads or a bayonet lock for securing the cap body onto the open end of the filler neck of the vehicle tank. The cap body has a centrally disposed opening for receiving the fuel nozzle of a corresponding fuel pump, this opening normally being covered by a spring-loaded closure flap hinged to the cap body. One such filler cap is screwed by the vehicle operator onto the filler neck of the fuel tank. To then fill the tank the fuel nozzle is inserted through the opening in the cap body to open the closure flap. After fuelling the fuel nozzle is removed from the opening of the cap body, resulting in the spring-loaded closure flap closing of its own accord. One such self-closing filler cap reads from and is claimed by U.S. Pat. No. 4,986,439, the entire text of which is expressly incorporated herein by reference.
When the fuel tank of an automotive vehicle is to be filled by an automatic fuelling system, for example by a robotic system, the fuel nozzle is no longer introduced by the vehicle operator through the opening of the cap body into the filler neck, but via a robotic arm capable of moving both vertically and horizontally for aligning the nozzle of a fuel pump with the filler neck of the fuel tank. Such alignment is faciliated by the use of a magnetic position sensor in the robotic arm. On completion of alignment the robotic arm extends the fuel nozzle towards the filler neck at an angle that is substantially at a right angle to the vehicle panel housing the filler neck. The robotic arm then extends the nozzle through the opening in the cap body and into the filler neck of the fuel tank by pushing down the closure flap in the cap. On vehicles that run exclusively on unleaded fuel, the fuel nozzle also needs to be extended through a second hinged flap in the filler neck before actual fuelling can commence On completion of automatic fuelling the robotic arm withdraws the fuel nozzle from the filler neck and out of the cap to allow both the restrictive flap in the filler neck and the closure flap in the cap to each resume its closed position.
In this arrangement it is necessary that the hinged mount of the restrictive flap in the filler neck and the hinged mount of the closure flap of the filler cap are arranged offset by approx. 180.sub.i to each other so that inserting the fuel nozzle into the filler neck as well as removing it therefrom and from the self-closing filler cap arranged thereon by the robotic arm can be sequenced so that no tilting or jamming at the restrictive flap or closure flap of the cap occurs. One particularly good example of such a self-closing filler cap for automatic fuelling reads from and is claimed by U.S. Pat. No. 5,720,328, the entire text of which is expressly incorporated herein by reference.
Although the filler cap claimed in this U.S. Pat. No. 5,720,328 has a proven record of success it has been found out that it cannot be put to use on all automotive vehicles, it having being discovered namely that the space available for applying the filler cap to the filler neck of the fuel tank is very small on some vehicles. This may then result in the hinged body lid closing off this space for access to the filler neck coming into contact with the filler cap secured to the filler neck.